Van Jones may have one of the hottest assignments in the Obama administration -- selling the notion of a new "green-collar" economy -- but in a country burdened with a 9.4 percent unemployment rate, it's not easy.

How do you tell an unemployed construction worker that it's time to start thinking about installing solar panels instead of aluminum siding? "I think some of these ideas are complicated for people when they first hear them," said Jones, senior green jobs adviser to the White House Council on Environmental Quality. Most people "don't know what retrofitting a building means, or they haven't heard of . . . a smart biofuel. And so a lot of times, people just sort of go yes, yes, but they aren't really following you."

Jones, 40, has been a leader in a growing movement that aims to hit two major social and policy challenges -- the struggling economy and environmental quality -- with one boulder. It's a vision that has been embraced by various industries and advocacy groups intrigued by the promise of thousands of new green jobs as the country invests in energy efficiency and confronts climate change.

But skeptics say the reality of creating a "green economy" is more complex. As with any new business, start-up costs are high -- and money is tight these days. And although the administration has allocated as much as $80 billion through the stimulus package to create more than 6 million green jobs, it is impossible at this point to quantify success. For one, there is no official federal definition of a green job -- though the president's budget includes money for the Bureau of Labor Statistics to work with other agencies to define the green economy and produce data on green-collar jobs by 2011.

Jones said anecdotal evidence is strong that the strategy is working, and he dismissed as "myth" reports that the plan merely moves jobs around the economy without creating new ones. "If you get people in on the ground floor of a growing industry, they can grow that industry," he said.

His career path was not unlike President Obama's. After graduating from Yale Law School, Jones worked as a community activist in Oakland, Calif., and founded the Ella Barker Center for Human Rights. A few years ago, he saw an opportunity to combine his commitment to racial and economic parity with work to solve the environmental crisis. He soon became a hero of the green movement as he talked about "greening the ghetto," appearing on hip shows such as "The Colbert Report" and sending out his message on YouTube.

"I think sometimes when we think about ecological solutions, we think about very high-end stuff -- you know, maybe space-age technology, way off in the future," he said. "What we forget is most of the things we need right now to reduce pollution, to reduce greenhouse gas emissions, don't require fancy technology. You know what it requires? A caulking gun."

He launched a Green-Collar Jobs Campaign, which led in 2007 to Green for All, an organization he founded to help create and find jobs in the green economy for the poor and disadvantaged. "People need to have the opportunity to be a part of industries that are going someplace," he said in an interview at his office across the street from the White House.

"When you're working in communities where people don't have a lot of hope for opportunity, you say, geez, [do you] you want to fight, but hard, to get people jobs that you know are going to be dead-end, or can you find them a job in a part of the economy that's going someplace? . . . And so then I saw that these firms were going places, that's when I got totally jazzed."